Xerographic plate holder



1954 T. c. MURRAY ETAL 3,143,044

XEROGRAPHIC PLATE HOLDER Filed Jan. 4, 1963 2 Sheets-Shet 1 INVENTOR THOMAS c. MURRAY Y ROBERT H. LIVA NORBETT H. KAUPP q V/ZMQ,

ATTORNEY 1964 T. c. MURRAY ETAL 3,143,044

XEROGRAPHIC PLATE HOLDER 2 Sheets-Sheet 2 Filed Jan. 4, 1963 rlllllllllllllflrllllld.

PLATEN VIEWING POSITION v INVENTOR. THOMAS C/MURRAY ROBERT H. LIVA NORBETT H. KAUPP A T TORNEY United States Patent Ofiicc 3,143,044 Patented Aug. 4,, 1964 XEROGRAPHIC PLATE HOLDE Thomas C. Murray and Robert H. Liva, Rochester, and Norbett H. Kaupp, Newark, N.Y., assignors to Xerox Corporation, Rochester, N.Y., a corporation of New York Filed Jan. 4, 1963, Ser. No. 249,381 3 Claims. (Cl. 95--1.7)

This invention relates to xerographic processing apparatus and particularly to an improved xerographlc plate holder.

More specifically, the invention relates to an improved .plate surface to a light image of the copy being reproduced, developing an image on the plate, transferring the image to a suitable support surface, fixing the image on the support surface and cleaning the plate for reuse. The xerographic plate, which consists of a layer of photocon- ,ductive insulating material on a conductive backing is placed in a camera and an electrical charge is placed uniformly on the photoconductive surface. When exposed to a light image, the electrostatic charge is discharged through the plate in the area exposed to light, leaving an electrostatic image configuration of the copy being reproduced on the plate surface. The plate is then developed with a toner material containing an electrostatic charge opposite to that of the plate. The toner material adheres to the plate in the areas containing the latent electrostatic charge, thus producing a powder image of the copy being reproduced. The transfer of the powder image to a support material and the cleaning of the plate for its reuse is accomplished by apparatus more fully described in the copending application, Serial No. 234,686, filed November 1, 1962.

'Manual, or semi-automatic xerographic reproducing equipment has received wide spread commercial acceptance for the reproduction of line copy, or half-tone images on paper or lithographic masters. However, a problem of major concern is the amount of time required to produce a completed reproduction.

Existing commercial equipment, though satisfactory for the purpose intended, requires the use of a wooden support frame to contain the xerographic plate and a dark slide or shield to protect the plate surface from surrounding light while the plate is being handled by an operator. The frame and the dark slide are costly, awkward to handle, and time consuming in the plate handling process. Also, in order to mount the plate in existing cameras, it is necessary to remove a Viewing platen from the camera frame and insert the xerographic plate with the wooden frame and the dark slide into the camera frame and then to withdraw the light shield from the plate frame. After exposure of the plate to a light image of the copy being reproduced, the dark slide is reinserted into the plate frame and the plate and frame are removed from the camera for further processing. Though this process achieves satisfactory results, the amount of time consumed and the cost of manufacturing the frame and shield are distinct limitations in the manufacture and operation of the machine. Further, the wooden plate frame and the dark slide are frequently damaged during usage, necessitating replacement.

It is therefore the primary object of this invention to improve xerographic plate holding means in a xerographic camera or processing unit.

It is a further object of this invention to improve xerographic plate holding means to reduce the amount of time required to mount a plate in a xerographic camera or processing unit.

It is a further object of this invention to eliminate a xerographic plate frame and to facilitate positioning of a xerographic plate in a camera or processing unit.

It is also an object of this invention to reduce the cost of manufacture of a xerographic plate used in a manual or semi-automatic xerographic reproducing machine.

These and other objects of this invention are attained by means of a plate holder pivotally connected to a xerographic camera or processing unit so that a xerographic plate may be moved between an operative, or processing position, and an inoperative, or leading and unloading position. The plate holder contains registration guides for proper alignment of the plate, and magnetic fasteners to hold the plate in position. The plate holder further contains a viewing platen pivotally mounted in the plate holder for movement to a viewing position and to a non-viewing position, where it will not interfere with the xerographic plate.

The invention is disclosed in the appended drawings, in which: 7

FIG. 1 is an isometric view of a xerographic camera, containing processing unit and plate holder, with the side covers broken away to show the internal structure;

FIG. 2 is an enlarged isometric view of the plate holder shown in FIG. 1;

FIG. 3 is a bottom view of a xerographic plate adapted for use in the plate holder shown in FIG. 2; and,

FIG. 4 is a side view of the plate holder taken substan tially along lines 44 of FIG. 2.

FIG. 1 shows an embodiment of a xerographic camera containing the invention disclosed herein. The camera contains three basic groups of elements generally indicated as a copy board 1, a lens mounting frame 2, and a processing unit 3. These members are positioned in alignment along a suitable support frame 4 and are en closed by appropriate covers 5. The covers 5 have been broken away to show the internal structure of the apparatus. These covers, however, are constructed to provide a light-tight enclosure around the entire camera mechanism.

The copy board 1 is mounted on frame 4 at one end of the camera and consists of a mounting board 6 and a plate of clear glass 7 contained in a frame member 8. The mounting board 6 and the glass frame 8 are of the same size and are positioned so that the surface of glass 7 is in contact with the flat surface of mounting board 6. Both the mounting board 6 and the frame 8 are pivotally attached to the frame member 4 and may be moved from a vertical to a horizontal position. The frame member 4 extends beyond the back of the mounting board 6 and provides support for the copy board assembly 1 when it is in a horizontal position. A pair of counterweights 9 are attached to the glass frame 8 by means of brackets 10. The counterweights 9 aid in moving the copy board as sembly 1 from a horizontal to a vertical position and serve to hold the copy board assembly 1 in a vertical position. The glass frame 8 is pivotally connected to the bottom of the mounting board 6 so that glass 7 and frame 8 may be moved to a vertical position, permitting the camera operator to place the copy to be reproduced on the mounting board 6. At this point, the glass 7 and frame 8 are moved from a vertical to a horizontal position and held against the mounting board 6 by means of latches graphic plate.

11. The entire copy board assembly including the glass 7, the mounting board 6 and the copy to be reproduced is moved to a vertical position wherein the copy to be reproduced is held in the same relative position on the mounting board by a pressure between the glass 7 and the mounting board 6. The copy is now in position to be reproduced by the camera.

A battery of illuminating lamps L1, L2, L-3 and L-4 are mounted on the frame 4 and directed to illuminate the copy in the board 1. Lamp L4 cannot be seen in FIG. 1. A small focusing lamp L5 is also mounted on frame 4 to illuminate the copy for focusing and adjustment purposes and to eliminate shadows on the copy when photographing paste-ups and visible record panels.

The lens mounting frame 2 contains an optical lens 13 which directs a reflected light image of the copy being reproduced into the processing unit 3 and onto a xerov The lens frame 2 is adapted to fit the covers 5 and the frame member 4 to provide a light seal, preventing any light from the illuminating lamps from reaching the developing and exposure mechanism, except through lens system 13. The lens board 2 is mounted in suitable brackets and rollers indicated at 14 and movably mounted on frame 4. The lens board 2 may be positioned relative to the copy board and the processing unit by moving it on the roller assembly 14 on frame 4, thus enabling the operator to adjust the focus and to provide the desired enlargement or reduction of the copy being reproduced. The mechanism to move the lens board externally of thecovers is not shownherein, however, any suitable mechanism, such as for example, a chain drive and a hand wheel or an electrical motor with the appropriate circuitry may be used.

The processing unit 3 is mounted on main frame member which contains a roller assembly generally indicated as 15 mounted on the support frame 4. The processing unit is likewise movable on frame 4 relative to the lens board and the copy board to provide proper focusing and enlargement or reduction, as desired. The external apparatus for moving the exposure and developing mechanism is not shown herein, but as in the case of the lens board, it may be any suitable moving means. A control panel, generally designated 16, is positioned adjacent to the processing unit 3 and, herein, shown as being on the covers 5 above the processing unit. However, the control panel 16 may be positioned at any location found desirable for operator convenience. A more complete description of the operation of the. camera and processing unit 3 may be found in application Serial No. 227,340, filed October 1, 1962, in the name of Thomas C. Murray et al.

The processing unit is adapted to receive a xerographic plate to beexposed and developed therein. 'It is necessary, therefore, to secure the xerographic plate in the opening 17 defined by a frame 18 in the processing unit 3. A pivotable plate holder generally indicated as 21 is attached to the processing unit by means of hinge members 23 and is movable from a horizontal position, as shown in FIG. 1, to a vertical or closed position wherein a xerographic plate 24 mounted on the plate holder 21 would cover and seal opening 17.

The hinges 23 are pivotally secured inside the processing unit 3 and extend outward to support the plate holder 21. The plate holder is secured to the hinges 23 by means of a pair of bolts 25 on each side thereof and spaced from the hinges 23 in the proper relative position to openings 17 by means of a pair of spacers 26 around each bolt 25. The plate holder 21consists basically of two side plates 22, a top plate 27, and a bottornplate 28. The top plate 27 is larger than the bottom plate 28 and gives the side View of the door, the shape of an inverted truncated triangle. The plate holder is shaped in this manner to permit movementof a viewing platen 29, discussed below.

When the plate holder 21 is in an open position, the hinges 23 rest'upon a pair of stops 30 which maintain the plate receiving surface in a substantially horizontal posi- 4 tion. A xerographic plate 24 may be placed on the then top surface as defined by the edge of side plates 22, top plate 27 and bottom plate 28. A pair of plate registration guides 31 are positioned one on each of the lower corners of the plate holder to provide vertical registration of the xerographic plate 24 and to support the xerographic plate as the plate holder is being moved toa vertical position. A pair of longitudinal registration guides 32 are positioned on each side of the plate holder to provide proper registration of the xerographic plate 24 in a longitudinal direction across the plate holder. Each registration guide contains a surface positioned to abut the edge of the xerographic plate and as shown herein, may also contain a surface parallel to the plate to support the plate when it is in the horizontal position. As the xerographic plate 24 is placed on the plate holder, the plate rests on the guide members 31 and 32 and abuts the vertical surfaces of the guide members to provide accurate registration of the plate with respect to the opening 17 and original copy on copy board 1.

After the plate 24 is positioned on the plate holder, properly abutting stops 31 and 32, the door is swung to a vertical position where it is latched in place by means of door latches 33 and 34. 'Latching the door in position forces. the xerographic plate 24 against a resilient seal 35 around the outer edge of opening 17. The seal 35 prevents loss of developer material from the processing unit, around the edge of the xerographic plate, and provides a light seal around the plate.

To hold a xerographic plate 24 rigidly in positions while being moved from a horizontal to a vertical position, there is located on either side of the plate holder 21 a pair of permanent magnets 36. The magnets 36 are secured in a mounting member 37 secured to the side plates 22. As seen in FIG. 3, a pair of blocks 38- are permanently secured to the back of the xerographic plate 24 in mating position to the magnets on the plate holder 21. The blocks 38 are constructed of steel or other suitable material for attraction by the magnets 36. The back of the xerographic plate is usually constructed of a material, such as aluminum, and therefore, is not attracted by the magnets 36., If the xerographic plate is constructed of magnetic material, the blocks 38 are not required. The magnetic blocks 38 fit into slots 43 cut in the top edge of the side plates 22. The slots 43 are the same depth as the thickness of the magnetic blocks 38 and the magnets 36 are positioned in a plane level with the bottom of the slots 43 so that the xerographic plate presses on the top edge of the side plates 22. The magnets 36 are pivotally secured in the frame members 37 at the middle of the magnet so that the magnetic members 36 may rock and align themselves parallel to the blocks 38 when the plate 24 is in position on plate holder 21. The magnetic members hold the plate in position while the plate holder is being moved between a horizontal or leading position and a vertical or operating position, and prevent any movement of the plate or damage to a powder image that may be on the plate. 7

Referring to FIG. 4, the door 21 also contains a viewing platen 29 of ground glass or some suitable material for viewing an image in the camera. Prior to placing a xerographic plate in the camera, the operator may move the plate holder 21 to a vertical position and View the image to be reproduced making adjustments for focusing or enlargement and reduction, as necessary. The viewing platen 29 is secured in a frame 39 which is pivotally fastened at its lower end by means of pin 40 mounted in the side plates 22. The top end of the viewing platen 29 is freely movable between the two positions shown by the solid and dotted lines in FIG. 4. r

The viewing platen 29 normally rests against a back plate 41, shown by the solid lines in FIG. 4. When the plate holder 21 is in a vertical position,-latched to the processing unit 3, the viewing platen 29 may be manually moved to a forward or viewing position, as shown by the dotted lines in FIG. 4. The platen 29 may be held in this position by any detent or latching means (not shown) to prevent undesired movement. Preferably, the latching means should be suchthat when the plate holder 21 is returned to a horizontal position, as shown in FIG. 2, the viewing platen 29 will fall under its own weight back against the back plate 41, so that the only manual operation required is in moving the platen from its at rest position to its forward or viewing position. When the platen 29 is moved to the viewing position, the bottom of the frame 39 abuts against the bottom plate 28 preventing movement beyond the vertical position. In this position, the viewing platen 29 is in the same relative position as the xerographic plate will be when mounted in a plate holder 21. The back plate 41 has a suitable aperture 42 cut therethrough to permit an operator to look through plate holder 21 to the surface of the viewing platen 29.

With the plate holder 21 in a vertical position and the viewing platen 29 in a forward or viewing position, a small lamp L-5, shown in FIG. 1, is illuminated and a light image of the original copy being reproduced is transmitted to the surface of the viewing platen. The operator may at this time adjust the relative position of the original copy on the copy board and he may adjust the position of lens board 2 of the processing unit 3 to effect proper focusing of the image. The latches 33 are disengaged from the catches 34 and the plate holder 21 is moved to a horizontal position wherein the viewing platen 29 in frame 39 falls to a non-viewing position i.e. back against back plate 41 and a xerographic plate may now be inserted onto the plate holder 21.

While the present invention as to its objects and advantages, as described herein, has been carried out in a specific embodiment thereof, it is not desired to be limited thereby, but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is:

1. In a Xerographic processing unit wherein a Xerographic plate is positioned during one or more xerographic processing steps,

a frame member for locating a xerographic plate in operative position during said processing steps,

a plate holder for supporting a Xerographic plate,

said plate holder being pivotally mounted on the frame member and arranged to move a xerographic plate 45 to a first position in which the plate is held in operative relation to the frame member and to a second position in which the plate is removed from operative relation with the frame member,

one or more plate positioning guides mounted on said plate holder to effect registration of a xerographic plate thereon,

and a pair of permanent magnets located on opposite sides of said plate holder and attached thereto, said permanent magnets being in register with magnetic members mounted on a Xerographic plate, whereby a Xerographic plate positioned on said plate holder is retained in a stable position thereon during movement of the plate holder between the first and second positions.

2. In a Xerographic processing unit wherein a Xerographic plate is positioned during one or more xerographic processing steps,

a frame member in said processing unit for locating a Xerographic plate in operative position during said processing steps,

a plate holder for supporting a xerographic plate,

said plate holder being pivotally mounted on said processing unit and arranged to move a Xerographic plate between a first position wherein the plate is in operative position against said frame member and a second position in which the plate is in an inoperative position and may be removed from said plate holder,

positioning guides mounted on said plate holder to effect registration of a Xerographic plate thereon,

magnetic latches located on said plate holder and adapted to register with magnetic portions of a xerographic plate whereby a Xerographic plate positioned on said plate holder is secured thereon during movement of the plate holder between said first and second positions,

and a viewing platen retained in said plate holder and movable within said plate holder between a first position wherein the viewing platen lies in a plane normally occupied by a Xerographic plate on said plate holder and a second position wherein the viewing platen does not interfere with a xerographic plate on said plate holder.

3. The apparatus of claim 2 wherein said viewing platen is adapted to fall to the viewing platen second position by its own weight when said plate holder is moved to the plate holder second position.

References Cited in the file of this patent UNITED STATES PATENTS 2,519,610 Sussin Aug. 22, 1950 2,619,418 Mayo Nov. 25, 1952 2,742,814 Gage Apr. 24; 1956 FOREIGN PATENTS 540,700 Great Britain Oct. 27, 1941 

1. IN A XEROGRAPHIC PROCESSING UNIT WHEREIN A XEROGRAPHIC PLATE IS POSITIONED DURING ONE OR MORE XEROGRAPHIC PROCESSING STEPS, A FRAME MEMBER FOR LOCATING A XEROGRAPHIC PLATE IN OPERATIVE POSITION DURING SAID PROCESSING STEPS, A PLATE HOLDER FOR SUPPORTING A XEROGRAPHIC PLATE, SAID PLATE HOLDER BEING PIVOTALLY MOUNTED ON THE FRAME MEMBER AND ARRANGED TO MOVE A XEROGRAPHIC PLATE TO A FIRST POSITION IN WHICH THE PLATE IS HELD IN OPERATIVE RELATION TO THE FRAME MEMBER AND TO A SECOND POSITION IN WHICH THE PLATE IS REMOVED FROM OPERATIVE RELATION WITH THE FRAME MEMBER, ONE OR MORE PLATE POSITIONING GUIDES MOUNTED ON SAID PLATE HOLDER TO EFFECT REGISTRATION OF A XEROGRAPHIC PLATE THEREON, AND A PAIR OF PERMANENT MAGNETS LOCATED ON OPPOSITE SIDES OF SAID PLATE HOLDER AND ATTACHED THERETO, SAID PERMANENT MAGNETS BEING IN REGISTER WITH MAGNETIC MEMBERS MOUNTED ON A XEROGRAPHIC PLATE, WHEREBY A XEROGRAPHIC PLATE POSITIONED ON SAID PLATE HOLDER IS RETAINED IN A STABLE POSITION THEREON DURING MOVEMENT OF THE PLATE HOLDER BETWEEN THE FIRST AND SECOND POSITIONS. 